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Title: Pedigree x-linked recessive/dominant Post by: dennagla on Mar 19, 2014 Family B: Non-syndromic deafness generally occurs due to a mutation in a single gene. The mutation has been identified in all living affected family members in the Family B pedigree below. Filled symbols indicate affected individuals; unfilled symbols indicate unaffected individuals.
Based on the information in the pedigree of Family B, is inheritance of this hearing loss trait consistent with an autosomal dominant or autosomal recessive pattern? (Tip: assume autosomal dominant and assign genotypes of affected and unaffected individuals, then assume autosomal recessive and assign genotypes of affected and unaffected individuals.) So my question is how do i figure out the genotypes for each one and also how do you tell if it is x-linked recessive or dominant? i'm attaching the picture of the pedigree, thank you! Title: Re: Pedigree x-linked recessive/dominant Post by: eilsh on Mar 24, 2014 The pedigree shows autosomal dominance.
If autosomal dominant, affected individual can be homozygous dominant or heterozygous for the trait. So, healthy Mom with affected heterozygous Dad, kid have 50% being affected. Or healthy Mom with affected homozygous Dad, kids will be 100% affected. If autosomal recessive, affected individual can only be homozygous recessive for the trait. So, healthy Mom x Affected Dad = carrier kids. Carrier mom x Affected Dad = kids 50% affected and 50% carrier. If X linked dominant, an affected male will always have affected daughters and healthy sons (assuming the mother is healthy). If X linked recessive, an affected female will always have affected sons, or a carrier female will have 50% chance affected sons. Affected males will always have carrier daughters. |